Question: Express your answer as a mixed number simplified to lowest terms. $18\dfrac{14}{20}-7\dfrac{2}{5} = {?}$
Answer: Separate the whole numbers from the fractional parts: $= {18} + {\dfrac{14}{20}} - {7} - {\dfrac{2}{5}}$ Bring the whole numbers together and the fractions together: $= {18} - {7} + {\dfrac{14}{20}} - {\dfrac{2}{5}}$ Subtract the whole numbers: $=11 + {\dfrac{14}{20}} - {\dfrac{2}{5}}$ Simplify each fraction: $= 11 + {\dfrac{7}{10}} - {\dfrac{2}{5}}$ Find a common denominator for the fractions: $= 11+\dfrac{7}{10}-\dfrac{4}{10}$ Subtract the fractions: $= 11+\dfrac{3}{10}$ Combine the whole and fractional parts into a mixed number: $= 11\dfrac{3}{10}$